NANOVNA, TinySA and SDRPlay

For those of us who like to mess with radios, but either can't afford or can't justify spending a lot of money on decent test equipment, I HIGHLY recommend getting a NANOVNA, TinySA and a software-defined receiver, such as the SDRPlay.  These 3 relatively inexpensive instruments (compared to the thousands similar test instruments would have cost a few years ago), and a DVM, will give you just about all you need to have an adequate test bench.

 See this excellent series on YouTube, from Kansas State University "MegawattKS":

NanoVNA and TinySA for Radio Design and others by them, and 

#313: Why a VNA needs to be calibrated | how to calibrate a nanoVNA, by Alan Wolke W2AEW

also:

TinySA 

NanoVNA 

SDRPlay

Recommendation:  Because the technology behind both the NanoVNA and TinySA is open-source, there are models for sale that both work and don't work.  As most of this stuff is made in China, your chances of getting a refund on something that doesn't work as the designers intended are doubtful.  A better choice is to take the advice of the designers and get these products from a reliable source.  Don't waste your money by trying to get a "bargain".  There are many unauthorized "clones" out there.